Midi In on the Sylphyo Receiver

What purpose does the Midi In port on the Sylphyo receiver serve?
Ive tried plugging in a midifootcontroller but the midi signals does not seem to be sent on thru the USB cable or detected by the Sylphyo instrument...?

The MIDI In can be used as a MIDI input when using the MIDI receiver as a standard Class Compliant USB MIDI interface.
This is only possible when the Sylphyo Controller is Off, as this input is replaced by the Wireless MIDI input when the Sylphyo is Off.